Delusion is commonly defined as a false belief and associated with psychiatric illness like schizophrenia, whereas confabulation is typically described as a false memory and associated with neurological disorder like amnesia. Yet delusion and confabulation both involve the endorsement of distorted representations of reality, whether about the present or the personal past. Moreover, differences in aetiology need not dictate mutual exclusivity with regard to underlying cognitive mechanisms. In response to the growing interest in commonalities and differences between delusion and confabulation, this Special Issue brings together contributors from diverse fields to consider the relations between these two symptoms. Although approaches and opinions differ, all of our contributors share common aims of clarifying theoretical conceptions and exploring boundaries so as to advance understanding of the cognitive neuropsychiatry of both delusion and confabulation. After introducing each contribution, we highlight some common themes and unanswered questions.